brain fried or on strike can't figure out which

[Allthunbs]

I want to learn some music for an upcoming (this weekend) massed band presentation. The problem is that I can't figure out which music to use. I have a choice of contrabasse but it's in treble clef (which I can't figure out), tuba cl? de FA, or tuba clef de sol. The two tuba parts are written in base clef. I'm using a Dynasty marching contrabasse in BBb.

I'm used to taking the treble clef music in french, dropping it down one octave plus two semitones and "adjusting" the key signature accordingly. Tonight, for some reason all of this has become a thorough muddle.

Thanks for the help